Pantograph engraving-machine.



No. 706,007. Patented Aug. 5, |902. M. BARR. PANTOGRAPH ENGRAVING MACHINE.

Applicat'on led Jan. 4, 1900.)

no Model.)

gir/653645. v [ni/07 60, 'W 12a" arr. Z per/MW lUNITED STATES PATENT OFFICE.

MARK BARR, OF BROADHEAT-H, ENGLAND, ASSIGNOR TO THE LINOTYPE COMPANY, LTD., OF LONDON, ENGLAND.

PANTOGRAPH ENGRAVING-NIACHINE.

SPECIFICATION forming part of Letters Patent No. 706,007', dated August 5, 1902.

Application filed J annary 4, 1900. Serial No. 344. (No model.)

To all whom, it may concer-1t:

Be it known that I, MARK BARR, of Broadheath, in the county of Chester, England,have invented certain new and useful Improvements in Pantograph Engraving-Machines;.

and I do hereby declare the following to be a full, clear, and eXact description of theinvention, such as will enable others skilled in the art to which it appertains to make and use the same.

The present invention relates to improvements in pantograph engraving-machines capable of dealing with three dimensionslength, width, and depthby a swinging and vertically-moving tracer-rod and horizontallymoving Work-table and verticallymoving tool.

The accompanying figure is a diagrammatic side elevation, partly in section. It does not include the means by which the swinging motions of the tracer-rod are converted into horizontal motions of the work-table, for the reason that these means do not form any part of the present invention. Any of the wellknown horizontally-acting pantographic linkages may be applied to the mechanism illustrated to eect such conversion.

The dimensions of length and width above mentioned are included hereinafter in the expression lateral movements or motions, and the dimension of depth is referred to as vertical movement or motion. Many of the movements of the tracer-point are neither truly lateral nor truly vertical,but compou nds of both. The lateral components of such movements are transmitted by the horizontally-acting pantographic linkage above mentioned and the vertical components by the mechanism of the present invention. The latter therefore consists in improved means for transmitting the vertical movements or the vertical components of the movements of the tracer-point to the tool and of means for preventingthe lateral movements or the lateral components of the movements of the tracer-point producing vertical movements in the tool. For convenience sake I will describe the latter part first.

A A are portions of the main frame of the machine.

a is the pattern having a projection l) on its surface. This projection is introduced into the ligure to show how the invention deals with it by the vertical movement of tracerpoint, so as to make the tool c reproduce it at b in the work CZ, which is carried by the work-table d. The tracer-rod is in two portions, which are connected together telescopically. The bottom portion l of it is outside the top portion 2 and slides overit. The connection between the two portions consists of two vertical slots 3 3 in the outer or bottom portion 1 and opposite to each other, a vhorizontal pin 4, passed through the bottom end of the inner portion 2 and engaging in the respective slots 3 3, and a ball 5, surrounding the bottom portion 1. The ball 5 is made fast to the above-mentioned pantographic linkage, and for that reason it c an move only in one and the same horizontal plane. The adjacent portion of this linkage is shown at d2. The bottom portion l is therefore capable of sliding freely through the said ball, while the top portion 2 is held to it by the engagement in it of the prolonged ends of the pin 4. The length of the pair of slots 3 3 is not less thany the maximum vertical movement or vertical component thereof, which is required of the tracer-point e. The top of the inner portion 2 swings by a ball-and-socket join-t 6 in a horizontal plate 7, capable of sliding in any horizontal direction in a guide 34, consisting of two parallel rings 35 35, standing at righty angles with two vertical guides 12 12, one on' each side of the guide 34:. These rings 35 are at such a distance apart from each other that the plate 7 can move horizontally only between them. The guides 12 enjoy a vertical sliding motion upon a pair of fixed standards 14 14n on the frame A. The top of the bottom portion l is likewise connected by a second ball-and-socket joint 10 to a second horizontal plate 11, capable of sliding in any horizontal direction in a guide 3G ofthe same construction as the guide 3l, already described, and which is made fast to the vertical guide 13 13 in the same way as the guide 34: to the guides v12 1"-2. These guides 13 13 are likewise capable of a vertical sliding motion on the said standards 14 14.

The tracer-rod l 2 swings as a whole in a ball-and-socket joint S, and through which it is capable of sliding vertically. This latter is the fulcrum of the tracer-rod and is carried bracketwise by a block 9, adapted to slide upon a fixed vert-ical guide 9, formed on the frame A, for the purpose of adjusting the ratio of lateral dimension between the pattern and the work. The said guide 9a and block 9 are provided with the usual scale and vernier, respectively.

15 is a lever having one end pivoted to the adjacent guide 12 at 16 and its opposite end pivoted on a fulcrum 17, fixed to the frame A, the pivot 16 being fast to the said guide and engaging in a horizontal slot 37 in the lever 15.

18 is a second lever having one end pivoted to the adjacent guide 13 at 19, this pivot 19 being fast to the said guide and engaging in a horizontal slot 38 in the lever 18.

The levers 15 and 18 are connected by a link 20, which has a vertical motion in a suitable part of the frame A, as in a guide, as shown. The said link is pivoted tothe lever 15 at 21 and to the lever 18 at 22. The pivots 21 and 22 are fast to the link 20, and engage, respectively, in horizontal slots 39 and in the levers 15 and 18. This point 22 is also the fulcrum of the lever 18, and upon this fulcrum it rocks only when there is vertical motion of the tracer-rod up or down a projection b on the pattern to be communicated to the tool c. The said lever 18 is connected to the tool c by the following means: 23 is a link from the saidlever, to which it is pivoted at 42, to the lever 24, which has its fulcrum 25 in a fixed pointon the said frame.

The link 23 slides in a guide in the frame A, as shown. j

26 is a link from the end of the lever 24 opposite to its fulcrum to one end of a lever 27, having its fulcrnm at 28 in the frame A and its opposite end pivoted at 29 to a rod 30, which carries the tool c and is capable of a reciprocating motion only in a guide 31 in the said frame A. The pivot 29 is fast to the rod 30 and engages in a horizontal slot 41 in the lever 27. The link 26 is adjustable horizontally along slots 32 33 in the levers 24 and 27, respectively, for ratio of vertical reduction between a projection b and its reproduction b' in the work d.

The above-mentioned lever 1S may rock upon the fulcrum 22 withontproducing any vertical motion in the rod 23, and this will often occur during purely lateral movements of the tracing-point. The movement is as follows: If the pivot 19 rises, it tends to push the rod 23 down; but if the moving fulcrum 22 vis raised proportionally as the pivot 19 rises then there is no downward motion imparted to the rod 23.

The invention. constructed as above described acts as follows: Vhen the point e of the tracer-rod 1 2 is moved horizontally over the pattern a,'the tracer-rod itself swings on its fulcrum 8. Let it be supposed that the motion of the point c is a lateral one from the center of the pattern toward one edge of it. The bottom portion 1 of the tracer-rod will slide down over the inner portion 2, because the ball 5 always moves in afixed horizontal plane, and move the guides 13 of the plate 11 down the standards 14. This motion of the guides 13, on which the lever 18 is pivoted, would beget'a vertical motion in the tool c, for which there is no cause in the pattern; but such motion is neutralized by the vertical component of thearcual motion of the ball of the joint 6, which ball is the top end of the compound tracer-rod 1 2. The guide 12 communicates this vertical motion of the plate 7 to the pivot 16, thereby dropping the pivot 21 a certain amount. This drop, which is of a certain length, is communicated to the pivot 22 by the link 20. The .proportions of the several levers are such that the said drop given, as described, to the pivot 22 is just enough to prevent the lever 18 moving the link 23 under the inuence of the above-described downward motion of the guides 13. Expressed numerically they are preferably as follows:

From a to center of` 10 2O From center of 5 to center of 6 12 VFrom pivot 19 to pivot 22 6 From pivot 22 to pivot 42 2 Frompivot 16 topivot21... (l Frompivot21 topivot 30 Other proportions are practicable; but the above may be regarded as typical as well as preferable.

Having described above how the present invention prevents the lateral movements or the lateral components of the movement of the tracerpoint e over the pattern a, producing any vertical motion in the tool c, Iwill proceed to describe how the vertical movements or the vertical components of the movements of the said point c are communicated to the said tool. The motion of the point e up the side of aprojection b has a vertical component. This vertical component is transmitted by the bottomportion 1 of the compound tracer-rod 1 2,sliding upward through the ball of the joint 8 to the guide 13, to which the lever 18 is pivoted, thereby rocking the said lever on its fulcrum 22, and thereby transmitting a proportional motion to the tool c through the link 23, lever 24, link 26,1ever 27, and rod 30. The fnlcrum 22 remains stationary, because the upward motion of the guides 13 is not communicated to the guides 12 and lever 15, and the reason why it is not communicated is that the bottom portion 1 of the tracerrod slides freely over the portion 2, and this lat ter is held by the pin 4 and ball 5 to the pantograph linkage already mentioned. So when the tracer-point c descends the projection b on the other side of it the downward motion of the portion 1 takes the guide 13 down with with it, sliding over the stationary portion 2 IOO in so doing and rocking the lever 1S, but without having disturbed the guides 12.

I claim- 1. The combination of swinging compound tracer-rod consisting of two portions telescopically connected together; two horizontal plates, one jointed to each portion of the said rod and capable of a reciprocating vertical motion; a lever-and-link mechanism from the horizontal plate of that portion of the tracerrod that carries the tracer-point, to the tool, adapted to transmit to the latter, the vertical movements or vertical components of the movements of the tracer-point; and a connection between the two horizon tal plates to prevent a lateral movement or a lateral component of a movement of the tracer-rod, producing a corresponding'vertical movement in the tool.

2. The hereinbeforedescribed combination of swinging compound tracer-rod having a bottom and outer portion adapted to slide over the top and inner portion; a connection fast to the said inner portion for limiting its motions to one and the same horizontal plane;

a horizontal plate jointed to the top end of the said top and inner portion and capable of a reciprocating Vertical motion; a horizontal plate jointed to the top end of the said bottom and outer portion and capable of a reciprocatin g vertical motion; a lever having a fixed fulcrum at one end and its opposite end connected to the horizontal plate of the said top and inner portion; a lever connected to the horizontal plate of the said bottom and outer portion of the tracer-rod; a link connecting the two levers and a link-and-lever mechanism establishing a connection between the last-mentioned lever and the tool to transmit the vertical movements or vertical componente of the movements of the said bottom and outer portion of the tracer-rod to the tool.

In testimony that I claim the foregoing as my invention I have Signed my name in presence of two subscribing witnesses.

MARK BARR. Witnesses:

THOMAS TAYLOR, HAROLD IsHERWooD. 

